Vibration screens used for coal separation have become absolutely necessary equipment for coal separating plants. Rapid wear of vibration screens and plugging of sieves, however, occur frequently. At present there are many types of vibration screens being used. Chinese Patent No. 97107249, entitled “Multiple Freedom Elastic Collision Type Screen Mat and Corresponding Sieving Technique” discloses an elastic rod and multiple freedom collision type screen mat and a corresponding sieving technique adaptable for dry sieving fine, particle-sized materials. The disclosed invention consists of many screen threads fixed on a screen mat frame, with the screen threads and frame holes clearance fit. The screen threads collide into a frame wall causing an instantaneous acceleration effect at the time of collision. The flowing of materials onto the screen surface causes the screen threads to continuously self clean, improves the loose effect of materials, increases sieving efficiency and lower limit of classification. As time passes, however, the holes in the screen become plugged, causing the frame to be unable to self clean. Chinese Patent No. 00253302, entitled “Dual Plastid Independently Supported Dual Drive Remittent Screen,” discloses an elastic screen mat mounted on a beam of an internal and external sieve box to produce a tensing and relaxing sieving motion. The screening surface allows for a large acceleration, is not easily plugged, and can be widely applied to material screening of metallurgic, mine, coal, building material, municipal garbage, and wastewater cleaning fields. Rapid wear of screening surface, however, is significant weak point of screen. Chinese Patent No. 02211871, entitled “Dual Vibration Large-Sized Round Vibration Screen,” discloses a large-sized round vibration screen with dual vibrators. The invention discloses a round vibration screen with two vibrators that rotate in parallel and have eccentric shafts of identical mass. The two vibrators move continuously and synchronistically through a tooth belt connection. If the vibrators are not increased in size, however, while the vibration strength of vibration screen is improved, the structure is too complicated, the manufacturing cost is high, and the energy consumption is huge. Chinese Patent No. 02112809, entitled “Hyperstatic Net Girder Excitation Large-Sized Vibration Screen,” discloses a hyperstatic net girder unit installed between the screen plates on two sides of the sieve box. The invention uses at least one piece of a hyperstatic support plate to connect multiple main girders and form into a container, and includes a vibration exciter on the vibration drive shaft on two sides of the hyperstatic support plate. As a result, the comprehensive properties are improved and the vibration is stable and can satisfy the process requirement of large-sized vibration screen, but the structure of machine is complicated, the mass participating in the vibration is big, and the energy consumption is huge.